code: def test_forward_loss(self):
      result = self.forward_wrapper(
          self.visual_model, self.visual_data, mode="loss"
      )
      self.assertIsInstance(result, dict)
  
      result = self.forward_wrapper(
          self.novisual_model, self.visual_data, mode="loss"
      )
      self.assertIsInstance(result, dict)
  
file_path: mmocr/tests/test_models/test_kie/test_extractors/test_sdmgr.py
imports: import copy
  import unittest
  from os.path import dirname, exists, join
  import torch
  from mmengine.config import Config, ConfigDict
  from mmengine.structures import InstanceData
  from mmocr.registry import MODELS
  from mmocr.structures import KIEDataSample
label_desc: Use image node_id 6 for calling the TestSDMGR obj's underlying member method code with example usage: obj.test_forward_loss() without return types